1. Field of the Invention
The present invention relates to using a 3-phase AC motor in a vehicle and more specifically to powering a 3-phase AC motor in a vehicle by charging a capacitor through the motor winding and then discharging the capacitor through the winding.
2. Background of the Invention
It is known in the art to use AC motors in vehicles such as automobiles, trucks and the like. Kinoshita in U.S. Pat. No. 5,629,603 discloses using an AC motor from a battery coupled to an inverter. Phase windings are connected to a triple pole contactor that is used to charge the battery. Young in U.S. Pat. No. 5,889,428 teaches a low-loss regulated charge pump with integrated ferroelectric capacitors. Grand in U.S. Published Application 2008/0169138 discloses an inverter that converts DC battery power to AC power. Multiple battery packs supply power to the vehicle. An AC motor is run from the AC power produced. U.S. Pat. Nos. 4,780,619 and 4,947,053 teach using transformers to produce 3-phase power for an AC 3-phase motor in a vehicle. U.S. Pat. No. 5,831,409 discloses using a 3-phase motor with two identical sets of windings.
It would be very desirable to be able to directly use stock 3-phase AC motors in vehicles. Such motors deliver considerable power and can be supplied in different sizes. Such motors have large torques at low RPMs and generally can run continuously at high RPM (around 3400 RPM for a typical 60 Hz motor). Speed can be controlled by adjusting drive frequency and by disabling one or more of the phases after the motor reaches a certain RPM.
Prior art systems have used expensive transformers or electronic drivers to achieve 3-phase power. It would be advantageous to be able to use 3-phase AC motors in vehicles without transformers or expensive drivers.